Tangshen formula modulates gut Microbiota and reduces gut-derived toxins in diabetic nephropathy rats

Gut Microbiota and Their Metabolites: The Hidden Driver of Diabetic Nephropathy? Unveiling Gut Microbe's Role in DN

BACKGROUND

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes with a complex pathogenesis.

METHODS

Recent studies were reviewed to explore the role of gut microbiota and its metabolites in DN development.

RESULTS

Dysbiosis of gut bacteria contributes to pathological changes such as glomerular sclerosis and renal tubule injury. Microbial metabolites are involved in DN through immune and inflammatory pathways.

CONCLUSIONS

Understanding the relationship between gut microbiota, its metabolites, and DN may offer potential implications for DN diagnosis, prevention, and treatment. Translating this knowledge into clinical practice presents challenges and opportunities.

Phenylethanol Glycosides from Cistanche tubulosa Modulate the Gut Microbiota and Cecal Metabolites to Ameliorate Diabetic Nephropathy Induced by Streptozotocin Combined with High-Fat Diet in Rats

Diabetic nephropathy (DN) is a prevalent complication and serious microvascular of diabetes mellitus. After previous studies, we found that phenylethanol glycosides (CPhGs) derived from Cistanche tubulosa (Schenk) Wight exerts antidiabetic and renoprotective effects. However, the effects of CPhGs on DN remain incompletely understood. The study aimed to examine the effects of CPhGs on DN in rats and explore the underlying mechanism involved. A DN rat model was established by streptozotocin (STZ) combined with a high-fat diet. Reagent kits were used to assess the extent to which CPhGs ameliorate hyperglycemia, insulin resistance (IR), renal dysfunction, kidney oxidative stress, and peripheral inflammation. Histology and immunohistochemical staining were used to detect the changes in renal tissue structure and the expression levels of α-smooth muscle actin (α-SMA) and collagen I. Furthermore, we analyzed the cecal contents of DN rats to investigate the effect of CPhGs on gut microbiota by using 16S rRNA sequencing and broad-spectrum metabolite profiling. The results showed that CPhGs demonstrated a range of advantageous outcomes in DN, encompassing the enhancement of kidney function and alleviation of hyperglycemia, IR, renal injury, oxidative stress, and peripheral inflammatory reactions. In addition, CPhGs regulated the abundance of the [Eubacterium]_coprostanoligenes_group, Oscillospiraceae_UCG-005, etc. to modulate the gut microbiota. CPhGs significantly upregulated the content of vitamin B6 and tyrosyl-tryptophan and downregulated histamine, L-methionine, etc. In summary, the therapeutic efficacy of CPhGs on DN rats may be achieved by modulating the gut microbiota and cecal metabolites to restore the metabolic disorders of vitamin B6, histidine, etc.

Gut-kidney interaction reinforces dapagliflozin-mediated alleviation in diabetic nephropathy

Intestinal microbiota are pathophysiologically involved in diabetic nephropathy (DN). Dapagliflozin, recognized for its blood glucose-lowering effect, has demonstrated efficacy in improving DN. However, the mechanisms beyond glycemic control that mediate the impact of dapagliflozin on DN remain unclear. Here, we investigated the effects of dapagliflozin on DN and gut microbiota, elucidating how it mitigates DN via the gut-kidney axis. Low-dose dapagliflozin markedly ameliorated renal inflammation and fibrosis and improved gut barrier function in high-fat diet (HFD)/streptozotocin (STZ)-induced DN mice and db/db mice without affecting blood glucose levels. These effects were associated with altered gut microbial composition and function. Eradication of the resident microbiota abolished the protective effects of dapagliflozin against kidney injury in DN mice. Moreover, dapagliflozin significantly altered microbial metabolites in DN mice, decreasing argininosuccinic acid (ASA) and palmitic acid (PA), while increasing S-allylcysteine (SAC) levels. ASA and PA increased the expression of renal inflammation- and fibrosis-related markers in HK-2 cells, whereas SAC ameliorated renal damage and altered the microbial composition in a manner similar to dapagliflozin in DN mice. Notably, Muribaculaceae and Desulfovibrionaceae were correlated with the alleviation of DN-associated renal dysfunction by low- and high-dose dapagliflozin treatments in DN mice. These findings demonstrate a potential application of dapagliflozin in managing DN by targeting the gut microbiota.NEW & NOTEWORTHY We demonstrated that dapagliflozin administration alleviated renal inflammation and fibrosis in vivo and in vitro, along with reshaping the gut microbiota composition and altering levels of key microbial metabolites, including argininosuccinic acid (ASA) and palmitic acid (PA), while increasing S-allylcysteine (SAC). Importantly, the genera Muribaculaceae and Desulfovibrionaceae emerged as pivotal microbial genera mediating the protective effects of dapagliflozin against diabetic nephropathy.

Exploration of the pathogenesis of nephrotic syndrome and traditional Chinese medicine intervention based on gut microbiota

Nephrotic syndrome (NS) represents a prevalent syndrome among various chronic kidney disease pathologies and is known for its higher severity and worse prognosis compared with chronic glomerulonephritis. Understanding its pathogenesis and identifying more effective treatment modalities have long been a concern of kidney specialists. With the introduction of the gut-kidney axis concept and the progress in omics technologies, alterations in the gut microbiota have been observed in primary and secondary NS. This link has been extensively researched in conditions such as diabetic nephropathy and immunoglobulin A (IgA) nephropathy. Thus, dysbiosis of the gut microbiota is seen as a crucial contributing factor in NS; however, there is a lack of comprehensive reviews that elucidate the changes in the gut microbiota across different NS conditions and that describe its mechanistic role in the disease. Moreover, serving as an innate regulator of the gut microbiota, traditional Chinese medicine (TCM) has the potential to exert a profound impact on the expression of inflammation-promoting agents, decreasing the levels of endotoxins and uremic toxins. In addition, it strengthens the stability of the intestinal barrier while controlling the metabolic function of the body through its efficient modulation of the gut microbiota. This intricate process yields far-reaching consequences for NS.

Traditional Chinese medicine improved diabetic kidney disease through targeting gut microbiota

CONTEXT

Diabetic kidney disease (DKD) affects nearly 40% of diabetic patients, often leading to end-stage renal disease that requires renal replacement therapies, such as dialysis and transplantation. The gut microbiota, an integral aspect of human evolution, plays a crucial role in this condition. Traditional Chinese medicine (TCM) has shown promising outcomes in ameliorating DKD by addressing the gut microbiota.

OBJECTIVE

This review elucidates the modifications in gut microbiota observed in DKD and explores the impact of TCM interventions on correcting microbial dysregulation.

METHODS

We searched relevant articles from databases including Web of Science, PubMed, ScienceDirect, Wiley, and Springer Nature. The following keywords were used: diabetic kidney disease, diabetic nephropathy, gut microbiota, natural product, TCM, Chinese herbal medicine, and Chinese medicinal herbs. Rigorous criteria were applied to identify high-quality studies on TCM interventions against DKD.

RESULTS

Dysregulation of the gut microbiota, including Lactobacillus, Streptococcus, and Clostridium, has been observed in individuals with DKD. Key indicators of microbial dysregulation include increased uremic solutes and decreased short-chain fatty acids. Various TCM therapies, such as formulas, tablets, granules, capsules, and decoctions, exhibit unique advantages in regulating the disordered microbiota to treat DKD.

CONCLUSION

This review highlights the importance of targeting the gut-kidney axis to regulate microbial disorders, their metabolites, and associated signaling pathways in DKD. The Qing-Re-Xiao-Zheng formula, the Shenyan Kangfu tablet, the Huangkui capsule, and the Bekhogainsam decoction are potential candidates to address the gut-kidney axis. TCM interventions offer a significant therapeutic approach by targeting microbial dysregulation in patients with DKD.

Liraglutide ameliorates diabetic kidney disease by modulating gut microbiota and L-5-Oxoproline

The gut microbiome-metabolites-kidney axis is a potential target for treating diabetic kidney disease (DKD). Our previous study found that Liraglutide attenuated DKD in rats by decreasing renal tubular ectopic lipid deposition (ELD) and serum metabolites levels, including L-5-Oxoproline (5-OP). However, the response of gut microbiome-metabolites-kidney axis to Liraglutide in DKD rats and the effect of 5-OP on ELD remain unknown. In this study, Sprague-Dawley rats were used as an animal model of DKD. They were subjected to a high fat diet, streptozotocin and uninephrectomy, followed by Liraglutide treatment (0.4 mg/kg d). Additionally, HK-2 cells were incubated with 30 mM glucose and 200 μM palmitate for 24h, and exposed to different concentrations of 5-OP. In DKD rats, Liraglutide dramatically improved the renal tubule structure. It increased the Simpson index (F = 4.487, p = 0.035) and reduced the Actinobacteria-to-Bacteroidetes ratio (F = 6.189, p = 0.014). At the genus level, Liraglutide increased the relative abundance of Clostridium, Oscillospira, Sarcina, SMB53, and 02d06 while decreasing that of Allobaculum. Meanwhile, 13 metabolites were significantly altered after Liraglutide treatment. Multi-omics analysis found that 5-OP levels were positively correlated with Clostridium abundance but negatively correlated with renal injury related indicators. In HK-2 cells, 5-OP significantly reduced the ELD in a dose-dependent manner through inhibiting the expression of SREBP1 and FAS. Overall, the renoprotective effect of Liraglutide in DKD rats is linked to the improvement of the gut microbiota composition and increased serum 5-OP levels, which may reduce ELD in renal tubular cells by lowering lipid synthesis.

The mechanisms underlying Chinese medicines to treat inflammation in diabetic kidney disease

ETHNIC PHARMACOLOGICAL RELEVANCE

Diabetic kidney disease (DKD) is the main cause of end-stage renal disease (ESRD), which is a public health problem with a significant economic burden. Serious adverse effects, such as hypotension, hyperkalemia, and genitourinary infections, as well as increasing adverse cardiovascular events, limit the clinical application of available drugs. Plenty of randomized controlled trials(RCTs), meta-analysis(MAs) and systematic reviews(SRs) have demonstrated that many therapies that have been used for a long time in medical practice including Chinese patent medicines(CPMs), Chinese medicine prescriptions, and extracts are effective in alleviating DKD, but the mechanisms by which they work are still unknown. Currently, targeting inflammation is a central strategy in DKD drug development. In addition, many experimental studies have identified many Chinese medicine prescriptions, medicinal herbs and extracts that have the potential to alleviate DKD. And part of the mechanisms by which they work have been uncovered.

AIM OF THIS REVIEW

This review aims to summarize therapies that have been proven effective by RCTs, MAs and SRs, including CPMs, Chinese medicine prescriptions, and extracts. This review also focuses on the efficiency and potential targets of Chinese medicine prescriptions, medicinal herbs and extracts discovered in experimental studies in improving immune inflammation in DKD.

METHODS

We searched for relevant scientific articles in the following databases: PubMed, Google Scholar, and Web of Science. We summarized effective CPMs, Chinese medicine prescriptions, and extracts from RCTs, MAs and SRs. We elaborated the signaling pathways and molecular mechanisms by which Chinese medicine prescriptions, medicinal herbs and extracts alleviate inflammation in DKD according to different experimental studies.

RESULTS

After overviewing plenty of RCTs with the low hierarchy of evidence and MAs and SRs with strong heterogeneity, we still found that CPMs, Chinese medicine prescriptions, and extracts exerted promising protective effects against DKD. However, there is insufficient evidence to prove the safety of Chinese medicines. As for experimental studies, Experiments in vitro and in vivo jointly demonstrated the efficacy of Chinese medicines(Chinese medicine prescriptions, medicinal herbs and extracts) in DKD treatment. Chinese medicines were able to regulate signaling pathways to improve inflammation in DKD, such as toll-like receptors, NLRP3 inflammasome, Nrf2 signaling pathway, AMPK signaling pathway, MAPK signaling pathway, JAK-STAT, and AGE/RAGE.

CONCLUSION

Chinese medicines (Chinese medicine prescriptions, medicinal herbs and extracts) can improve inflammation in DKD. For drugs that are effective in RCTs, the underlying bioactive components or extracts should be identified and isolated. Attention should be given to their safety and pharmacokinetics. Acute, subacute, and subchronic toxicity studies should be designed to determine the magnitude and tolerability of side effects in humans or animals. For drugs that have been proven effective in experimental studies, RCTs should be designed to provide reliable evidence for clinical translation. In a word, Chinese medicines targeting immune inflammation in DKD are a promising direction.

Mizhuo Guanchangye enema delays the decline of renal function in rats with chronic kidney disease by intervening in the TLR4/MyD88/NF-κB pathway

Background

Chronic kidney disease (CKD) is a prevalent chronic condition that poses a significant threat to human health. There is a close connection between the gut and kidneys, jointly influencing the onset and progression of CKD through the "gut-kidney axis." Traditional Chinese medicine has shown potential in CKD treatment, but the specific mechanisms require further investigation.

Objectives

This study aims to explore the protective effects of Mizhuo Enema (MZGCY) on kidney function in CKD rats by regulating the TLR4/MyD88/NF-κB signaling pathway.

Methods

The researcher employed a CKD rat model, which was divided into four groups: Control, Model, half-dose Mizhuo Guanchangye (1/2 MZGCY), and full-dose Mizhuo Guanchangye (MZGCY). Post enema administration, assessments were conducted on kidney function indicators, which included blood urea nitrogen (BUN), serum creatinine (SCR), and 24-h urinary protein. Additionally, measurements were taken for intestinal toxic substances such as indoxyl sulfate (IS) and lipopolysaccharide (LPS), as well as inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Examinations of pathological changes in both the intestines and kidneys were also performed. During this process, immunofluorescence was utilized to detect the expression levels of proteins toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), and nuclear factor kappa B (NF-κB) in the intestinal tissues.

Results

It was found that after enema treatment, the BUN, SCR, and 24-h urinary protein levels in the MZGCY and 1/2 MZGCY groups significantly decreased, indicating notable improvement in kidney function. Compared to the model group, the IS, LPS, IL-6, and TNF-α levels in the MZGCY and 1/2 MZGCY groups were significantly reduced. Immunofluorescence showed a marked decrease in the expression of TLR4, MyD88, and NF-κB proteins in the intestines of the MZGCY group.

Conclusion

MZGCY significantly reduces the levels of intestinal toxins and inflammatory factors in the serum of CKD rats by interfering with the TLR4/MyD88/NF-κB signaling pathway, thereby improving intestinal and renal pathological changes and delaying CKD progression. This study demonstrates that MZGCY has significant renal protective effects, providing a new potential approach for CKD treatment.

Barleriside A, an aryl hydrocarbon receptor antagonist, ameliorates podocyte injury through inhibiting oxidative stress and inflammation

INTRODUCTION

Increasing evidence shows that hyperactive aryl hydrocarbon receptor (AHR) signalling is involved in renal disease. However, no currently available intervention strategy is effective in halting disease progression by targeting the AHR signalling. Our previous study showed that barleriside A (BSA), a major component of Plantaginis semen, exhibits renoprotective effects.

METHODS

In this study, we determined the effects of BSA on AHR expression in 5/6 nephrectomized (NX) rats. We further determined the effect of BSA on AHR, nuclear factor kappa B (NF-ƙB), and the nuclear factor erythroid 2-related factor 2 (Nrf2) signalling cascade in zymosan-activated serum (ZAS)-stimulated MPC5 cells.

RESULTS

BSA treatment improved renal function and inhibited intrarenal nuclear AHR protein expression in NX-treated rats. BSA mitigated podocyte lesions and suppressed AHR mRNA and protein expression in ZAS-stimulated MPC5 cells. BSA inhibited inflammation by improving the NF-ƙB and Nrf2 pathways in ZAS-stimulated MPC5 cells. However, BSA did not markedly upregulate the expression of podocyte-specific proteins in the ZAS-mediated MPC5 cells treated with CH223191 or AHR siRNA compared to untreated ZAS-induced MPC5 cells. Similarly, the inhibitory effects of BSA on nuclear NF-ƙB p65, Nrf2, and AHR, as well as cytoplasmic cyclooxygenase-2, heme oxygenase-1, and AHR, were partially abolished in ZAS-induced MPC5 cells treated with CH223191 or AHRsiRNA compared with untreated ZAS-induced MPC5 cells. These results indicated that BSA attenuated the inflammatory response, partly by inhibiting AHR signalling.

DISCUSSION

Both pharmacological and siNRA findings suggested that BSA mitigated podocyte lesions by improving the NF-ƙB and Nrf2 pathways via inhibiting AHR signalling. Therefore, BSA is a high-affinity AHR antagonist that abolishes oxidative stress and inflammation.

The Antidiabetic Potential of Probiotics: A Review

Diabetes has become one of the most prevalent global epidemics, significantly impacting both the economy and the health of individuals. Diabetes is associated with numerous complications, such as obesity; hyperglycemia; hypercholesterolemia; dyslipidemia; metabolic endotoxemia; intestinal barrier damage; insulin-secretion defects; increased oxidative stress; and low-grade, systemic, and chronic inflammation. Diabetes cannot be completely cured; therefore, current research has focused on developing various methods to control diabetes. A promising strategy is the use of probiotics for diabetes intervention. Probiotics are a class of live, non-toxic microorganisms that can colonize the human intestine and help improve the balance of intestinal microbiota. In this review, we summarize the current clinical studies on using probiotics to control diabetes in humans, along with mechanistic studies conducted in animal models. The primary mechanism by which probiotics regulate diabetes is improved intestinal barrier integrity, alleviated oxidative stress, enhanced immune response, increased short-chain fatty acid production, etc. Therefore, probiotic supplementation holds great potential for the prevention and management of diabetes.

Ramulus Mori (Sangzhi) Alkaloids Alleviate Diabetic Nephropathy through Improving Gut Microbiota Disorder

Diabetic nephropathy (DN), one of the leading causes of end-stage kidney failure worldwide, is closely associated with high mortality in diabetic patients. However, therapeutic drugs for DN are still lacking. Ramulus Mori alkaloids (SZ-A), an effective component of alkaloids extracted from Ramulus Mori, have been found to improve glucose and lipid metabolism to mitigate diabetes and obesity; however, few studies have focused on their effects on DN progression. Thus, we investigated the protective role of SZ-A on DN through 16S rRNA sequencing, non-targeted metabolomics, and fecal microbiota transplantation (FMT) experiments. To address our hypothesis, we established the DN mouse model by combining a high-fat diet (HFD) with streptozotocin (STZ) injection. Herein, we demonstrated that SZ-A supplementation was recalcitrant to renal injury in DN mice, improving glomerular morphology, reversing the blood biochemistry parameters, and ameliorating podocyte injury. Importantly, the composition of the gut microbiota altered after SZ-A treatment, especially with the elevated abundance of Dubosiella and the increased level of serum pentadecanoic acid. FMT experiments further revealed that the gut microbiota exerted critical effects in mediating the beneficial roles of SZ-A. In vitro experiments proved that pentadecanoic acid administration improved podocyte apoptosis induced by AGEs. Taken together, SZ-A play a renoprotective role, possibly through regulating the gut microbiota and promoting pentadecanoic acid production. Our current study lends support to more extensive clinical applications of SZ-A.

Tangshen Formula alleviates inflammatory injury against aged diabetic kidney disease through modulating gut microbiota composition and related amino acid metabolism

Diabetic kidney disease (DKD) is leading causes and one of the fastest growing causes of chronic kidney disease worldwide, and leads to high morbidity and mortality. Emerging evidences have revealed gut microbiota dysbiosis and related metabolism dysfunction play a dominant role in DKD progression and treatment through modulating inflammation. Our previous studies showed that Tangshen Formula (TSF), a Chinese herbal prescription, exhibited anti-inflammatory effect on DKD, but underlying mechanism that involved gut microbiota and related metabolism in aged model remained obscure. Here, BTBR ob/ob mice were used to establish aged DKD model, and 16S rRNA sequence and untargeted metabolomic analyses were employed to investigate the correlation between colonic microbiota and serum metabolism. The aged ob/ob mice exhibited obvious glomerular and renal tubule injury and kidney function decline in kidney, while TSF treatment significantly attenuated these abnormalities. TSF also exhibited potent anti-inflammatory effect in aged ob/ob mice indicating by reduced proinflammatory factor IL-6 and TNF-α, MCP-1 and COX-2 in serum, kidney and intestine, which suggested the involvement of gut microbiota with TSF effect. The 16S rDNA sequencing of the colonic microbiome and untargeted serum metabolomics analysis revealed significant differences in gut microbiota structure and serum metabolomic profiles between WT and ob/ob mice. Notably, TSF treatment reshaped the structure of gut microbiota and corrected the disorder of metabolism especially tryptophan metabolism and arginine biosynthesis. TSF increased Anaeroplasma and Barnesiella genera and decreased Romboutsia, Akkermansia, and Collinsella genera, and further elevated tryptophan, 5-hydroxyindoleacetate, glutamic acid, aspartate and reduced 4-hydroxy-2-quinolinecarboxylic acid, indole-3-acetic acid, xanthurenic acid, glutamine. Further correlation analysis indicated that disturbed gut microbiota was linked to tryptophan metabolism and arginine biosynthesis to regulate inflammation in aged DKD. Our data revealed that TSF attenuated renal inflammation by modulating gut microbiota and related amino acid metabolism in aged DKD model, highlighting gut microbiota and related metabolism functioned as potential therapeutic target for DKD in elderly patients.

Uremic toxins mediate kidney diseases: the role of aryl hydrocarbon receptor

Aryl hydrocarbon receptor (AhR) was originally identified as an environmental sensor that responds to pollutants. Subsequent research has revealed that AhR recognizes multiple exogenous and endogenous molecules, including uremic toxins retained in the body due to the decline in renal function. Therefore, AhR is also considered to be a uremic toxin receptor. As a ligand-activated transcriptional factor, the activation of AhR is involved in cell differentiation and senescence, lipid metabolism and fibrogenesis. The accumulation of uremic toxins in the body is hazardous to all tissues and organs. The identification of the endogenous uremic toxin receptor opens the door to investigating the precise role and molecular mechanism of tissue and organ damage induced by uremic toxins. This review focuses on summarizing recent findings on the role of AhR activation induced by uremic toxins in chronic kidney disease, diabetic nephropathy and acute kidney injury. Furthermore, potential clinical approaches to mitigate the effects of uremic toxins are explored herein, such as enhancing uremic toxin clearance through dialysis, reducing uremic toxin production through dietary interventions or microbial manipulation, and manipulating metabolic pathways induced by uremic toxins through controlling AhR signaling. This information may also shed light on the mechanism of uremic toxin-induced injury to other organs, and provide insights into clinical approaches to manipulate the accumulated uremic toxins.

Colonic microflora and plasma metabolite-based comparative analysis of unilateral ureteral obstruction-induced chronic kidney disease after treatment with the Chinese medicine FuZhengHuaYuJiangZhuTongLuo and AST-120

Background

Many researchers have investigated the use of Chinese herbs to delay the progression of chronic kidney disease (CKD) through their effects on colonic microflora and microbiota-derived metabolites. However, whether FuZhengHuaYuJiangZhuTongLuo (FZHY) has effects that are similar to those of AST-120 on CKD needs to be elucidated.

Methods

In this study, we compared the effects of FZHY and AST-120 on the colonic microbiota and plasma metabolites in the CKD rat model. We developed a unilateral ureteral obstruction (UUO)-induced CKD rat model and then administered FZHY and AST-120 to these model rats. Non-targeted metabolomic LC-MS analysis, 16S rRNA sequencing, and histopathological staining were performed on plasma, stool, and kidney tissues, respectively, and the joint correlation between biomarkers and metabolites of candidate bacteria was analyzed.

Results

Our results showed that administering FZHY and AST-120 effectively ameliorated UUO-induced abnormal renal function and renal fibrosis and regulated the composition of microbiota and metabolites. Compared to the UUO model group, the p_Firmicutes and o_Peptostreptococcales_Tissierellales were increased, while 14 negative ion metabolites were upregulated and 21 were downregulated after FZHY treatment. Additionally, 40 positive ion metabolites were upregulated and 63 were downregulated. On the other hand, AST-120 treatment resulted in an increase in the levels of g_Prevotellaceae_NK3B31_group and f_Prevotellaceae, as well as 12 upregulated and 23 downregulated negative ion metabolites and 56 upregulated and 63 downregulated positive ion metabolites. Besides, FZHY increased the levels of candidate bacterial biomarkers that were found to be negatively correlated with some poisonous metabolites, such as 4-hydroxyretinoic acid, and positively correlated with beneficial metabolites, such as l-arginine. AST-120 increased the levels of candidate bacterial biomarkers that were negatively correlated with some toxic metabolites, such as glycoursodeoxycholic acid, 4-ethylphenol, and indole-3-acetic acid.

Conclusion

FZHY and AST-120 effectively reduced kidney damage, in which, the recovery of some dysregulated bacteria and metabolites are probably involved. As their mechanisms of regulation were different, FZHY might play a complementary role to AST-120 in treating CKD.

Traditional Chinese medicine for the treatment of immune-related nephropathy: A review

Immune-related nephropathy (IRN) refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure. The pathogenesis of IRN is not fully understood; therefore, treatment is challenging. Traditional Chinese medicines (TCMs) have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy, lupus nephropathy, and diabetic nephropathy. The underlying mechanisms mainly include its inhibition of inflammation; improvements to renal interstitial fibrosis, oxidative stress, autophagy, apoptosis; and regulation of immunity. In this review, we summarize the clinical symptoms of the three IRN subtypes and the use of TCM prescriptions, herbs, and bioactive compounds in treating IRN, as well as the potential mechanisms, intending to provide a reference for the future study of TCM as IRN treatments.

Role of Gut Microbiota, Immune Imbalance, and Allostatic Load in the Occurrence and Development of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a prevailing complication arising from diabetes mellitus. Unfortunately, there are no trustworthy and efficacious treatment modalities currently available. In recent times, compelling evidence has emerged regarding the intricate correlation between the kidney and the gut microbiota, which is considered the largest immune organ within the human physique. Various investigations have demonstrated that the perturbation of the gut microbiota and its associated metabolites potentially underlie the etiology and progression of DKD. This phenomenon may transpire through perturbation of both the innate and the adaptive immunity, leading to a burdensome allostatic load on the body and ultimately culminating in the development of DKD. Within this literature review, we aim to delve into the intricate interplay between the gut microbiota, its metabolites, and the immune system in the context of DKD. Furthermore, we strive to explore and elucidate potential chemical interventions that could hold promise for the treatment of DKD, thereby offering invaluable insights and directions for future research endeavors.

Astragalus membranaceus and Salvia miltiorrhiza ameliorate diabetic kidney disease via the "gut-kidney axis"

BACKGROUND

The combination of Astragalus membranaceus and Salvia miltiorrhiza (AS) is an effective prescription for treating diabetic kidney disease (DKD) in traditional Chinese medicine. Its efficacy in treating DKD has been confirmed, but the potential regulatory mechanism has not yet been fully clarified.

PURPOSE

To explore the mechanism by which AS regulates the "gut-metabolism-transcription" coexpression network under the action of the "gut-kidney axis" to ameliorate DKD.

METHODS

SD rats were used to establish the DKD model by injecting STZ. After AS intervention, the structure and function of the kidney and colon were observed. We sequenced the gut microbiota utilizing 16S rDNA, identified serum differential metabolites using LC‒MS/MS, and observed renal mRNA expression by RNA seq. The "gut-metabolism-transcription" coexpression network was further constructed, and the target bacteria, target metabolites, and target genes of AS were ultimately screened and validated.

RESULTS

AS improved renal pathology and functional damage and increased the abundance of Akkermansia, Akkermansia_muciniphila, Lactobacillus and Lactobacillus_murinus. Fourteen target metabolites of AS were identified, which were mainly concentrated in 19 KEGG pathways, including sphingolipid metabolism and glycerophospholipid metabolism. Sixty-three target mRNAs of AS were identified. The top 20 pathways were closely related to glycolipid metabolism, and 14 differential mRNAs were expressed in these pathways. Correlation analysis showed that Akkermansia, Akkermansia muciniphila, Lactobacillus and Lactobacillus murinus were closely associated with sphingolipid metabolism, glycerophospholipid metabolism, arachidonic acid metabolism, ascorbate and aldarate metabolism and galactose metabolism. Moreover, the target metabolites and target mRNAs of AS were also enriched in five identical pathways of sphingolipid metabolism, glycerophospholipid metabolism, arachidonic acid metabolism, ascorbate and aldarate metabolism and galactose metabolism, including 8 different metabolites, such as sphingosine, and 5 different genes, such as Kng1. The 8 metabolites had high AUC prediction values, and the validation of the 5 genes was consistent with the sequencing results.

CONCLUSION

Our research showed that AS can improve DKD via the "gut-kidney axis". Akkermansia muciniphila and Lactobacillus murinus were the main driving bacteria, and five pathways related to glycolipid metabolism, especially sphingolipid metabolism and glycerophospholipid metabolism, may be important follow-up reactions and regulatory mechanisms.

The intellectual base and global trends in inflammation of diabetic kidney disease: a bibliometric analysis

Diabetic kidney disease (DKD) is a severe complication of diabetes mellitus (DM). The literature on DKD inflammation research has experienced substantial growth. However, there is a lack of bibliometric analyses. This study aimed to examine the existing research on inflammation in DKD by analyzing articles published in the Web of Science Core Collection (WOSCC) over the past 30 years. We conducted a visualization analysis using several software, including CiteSpace and VOSviewer. We found that the literature on inflammation research in DKD has experienced substantial growth, indicating a rising interest in this developing area of study. In this field, Navarro-Gonzalez, JF is the most frequently cited author, Kidney International is the most frequently cited journal, China had the highest number of publications in the field of DKD inflammation, and Monash University emerged as the institution with the most published research. The research area on inflammation in DKD primarily centers around the investigation of 'Glycation end-products', 'chronic kidney disease', and 'diabetic nephropathy'. The emerging research trends in this field will focus on the 'Gut microbiota', 'NLRP3 inflammasome', 'autophagy', 'pyroptosis', 'sglt2 inhibitor', and 'therapeutic target'. Future research on DKD may focus on further exploring the inflammatory response, identifying specific therapeutic targets, studying biomarkers, investigating stem cell therapy and tissue engineering, and exploring gene therapy and gene editing. In summary, this study examines the main areas of study, frontiers, and trends in DKD inflammation, which have significant implications for future research.

Effect of Tangshen formula on the remodeling of small intestine and colon in Zucker diabetic fatty rats

Background and aim

Previous study have demonstrated that Tangshen Formula (TSF) could attenuate colonic histomorphological remodeling in the diabetic rat model induced by high fat diet plus low dosage streptozotocin (STZ). However, it is not clear whether TSF has same effect on small intestine and the effect on biomechanical properties of bowel. The aim of this study is to investigate the effect of TSF on histomorphological and biomechanical remodeling of small intestine and colon by using Zucker Diabetic Fatty (ZDF) Rat model.

Materials and methods

ZDF rats (obese fa/fa) with blood glucose higher than 11.7 mmol/L were divided into ZDF group (diabetic control group) and ZDF + TSF group (TSF treatment group), the later were intragastrically administered TSF. The ZDF rats (lean fa/+) were served as normal control (ZL) group. The rats in the ZL and ZDF groups were administered with saline. The experimental period covered from 8 weeks to 24 weeks. At the end of experiment, the ileal and colonic segments were studied in vitro. The histomorphometry and biomechanical parameters were measured.

Results

Compared with ZL group histomorphologically, the wet weight per unit length, wall thickness, wall area and fractions of total and type I and type III collagen in different layers for both ileum and colon increased in ZDF group. Those increasing parameters were partially inhibited in ZDF + TSF group. Compared with ZL group biomechanically, ZDF and ZDF + TSF groups had smaller opening angle and residual strain in ileum, and bigger opening angle and residual strain in colon. Whereas the wall became softer in circumferential direction and stiffer in longitudinal direction for both ileum and colon. However, no difference of biomechanical parameters was found between ZDF and ZDF + TSF groups.

Conclusion

The histomorphological and biomechanical remodeling of ileum and colon were happened in ZDF rats （obese fa/fa）. TSF could partly attenuate ileal and colonic histomorphological remodeling rather than biomechanical remodeling.

Moshen granule ameliorates membranous nephropathy by regulating NF-ƙB/Nrf2 pathways via aryl hydrocarbon receptor signalling

Considerable achievements were realized in illuminating underlying pathological mechanisms of patients with idiopathic membranous nephropathy (IMN). Although IMN patients are well diagnosed before they reach renal failure, no currently available drug intervention is effective in halting IMN progression. In this study, we assess Moshen granule (MSG) effect on IMN patients and cationic bovine serum albumin (CBSA)-induced rats. Increasing studies has indicated that activation of aryl hydrocarbon receptor (AHR) was related to oxidative stress and inflammation. We further determine MSG effect on AHR, nuclear factor ƙB (NF-ƙB) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the CBSA-induced rats. MSG markedly reduces proteinuria and improves kidney function in both IMN patients and rats induced by CBSA. MSG markedly inhibits increased mRNA expressions of intrarenal AHR and its four downstream target genes including CYP1A1, CYP1A2, CYP1B1 and COX-2 compared with untreated CBSA-induced rats. This is accompanied by markedly downregulated protein expressions of p-IƙBα and NF-ƙB p65 and its downstream gene products including MCP-1, COX-2, 12-LOX, iNOS, p47phox and p67phox, while markedly preserves protein expressions of Nrf2 and its downstream gene products including catalase, HO-1, GCLM, GCLC, MnSOD and NQO1 in the kidney tissues. These data suggests MSG blunts podocyte damage through inhibiting activation of NF-ƙB/Nrf2 pathway via AHR signaling. This finding may provide a promising therapy for treatment of IMN through oxidative stress and inflammation.

The roles of gut microbiota and its metabolites in diabetic nephropathy

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes, which increases the risk of renal failure and causes a high global disease burden. Due to the lack of sustainable treatment, DN has become the primary cause of end-stage renal disease worldwide. Gut microbiota and its metabolites exert critical regulatory functions in maintaining host health and are associated with many pathogenesis of aging-related chronic diseases. Currently, the theory gut-kidney axis has opened a novel angle to understand the relationship between gut microbiota and multiple kidney diseases. In recent years, accumulating evidence has revealed that the gut microbiota and their metabolites play an essential role in the pathophysiologic processes of DN through the gut-kidney axis. In this review, we summarize the current investigations of gut microbiota and microbial metabolites involvement in the progression of DN, and further discuss the potential gut microbiota-targeted therapeutic approaches for DN.

Intestinal microbiome diversity of diabetic and non-diabetic kidney disease: Current status and future perspective

A significant portion of the health burden of diabetic kidney disease (DKD) is caused by both type 1 and type 2 diabetes which leads to morbidity and mortality globally. It is one of the most common diabetic complications characterized by loss of renal function with high prevalence, often leading to acute kidney disease (AKD). Inflammation triggered by gut microbiota is commonly associated with the development of DKD. Interactions between the gut microbiota and the host are correlated in maintaining metabolic and inflammatory homeostasis. However, the fundamental processes through which the gut microbiota affects the onset and progression of DKD are mainly unknown. In this narrative review, we summarised the potential role of the gut microbiome, their pathogenicity between diabetic and non-diabetic kidney disease (NDKD), and their impact on host immunity. A well-established association has already been seen between gut microbiota, diabetes and kidney disease. The gut-kidney interrelationship is confirmed by mounting evidence linking gut dysbiosis to DKD, however, it is still unclear what is the real cause of gut dysbiosis, the development of DKD, and its progression. In addition, we also try to distinguish novel biomarkers for early detection of DKD and the possible therapies that can be used to regulate the gut microbiota and improve the host immune response. This early detection and new therapies will help clinicians for better management of the disease and help improve patient outcomes.

Gut microbiota and its metabolites - molecular mechanisms and management strategies in diabetic kidney disease

Diabetic kidney disease (DKD) is one of the major microvascular complications of diabetes mellitus and is also one of the serious risk factors in cardiovascular events, end-stage renal disease, and mortality. DKD is associated with the diversified, compositional, and functional alterations of gut microbiota. The interaction between gut microbiota and host is mainly achieved through metabolites, which are small molecules produced by microbial metabolism from exogenous dietary substrates and endogenous host compounds. The gut microbiota plays a critical role in the pathogenesis of DKD by producing multitudinous metabolites. Nevertheless, detailed mechanisms of gut microbiota and its metabolites involved in the occurrence and development of DKD have not been completely elucidated. This review summarizes the specific classes of gut microbiota-derived metabolites, aims to explore the molecular mechanisms of gut microbiota in DKD pathophysiology and progression, recognizes biomarkers for the screening, diagnosis, and prognosis of DKD, as well as provides novel therapeutic strategies for DKD.

Natural products from plants and microorganisms: Novel therapeutics for chronic kidney disease via gut microbiota regulation

Dysbiosis of gut microbiota plays a fundamental role in the pathogenesis and development of chronic kidney disease (CKD) and its complications. Natural products from plants and microorganisms can achieve recognizable improvement in renal function and serve as an alternative treatment for chronic kidney disease patients with a long history, yet less is known on its beneficial effects on kidney injury by targeting the intestinal microbiota. In this review, we summarize studies on the effects of natural products from plants and microorganisms, including herbal medicines and their bioactive extracts, polysaccharides from plants and microorganisms, and phytochemicals, on the prevention and treatment of chronic kidney disease through targeting gut microflora. We describe the strategies of these anti-CKD effects in animal experiments including remodulation of gut microbiota structure, reduction of uremic toxins, enhancement of short-chain fatty acid (SCFA) production, regulation of intestinal inflammatory signaling, and improvement in intestinal integrity. Meanwhile, the clinical trials of different natural products in chronic kidney disease clinical practice were also analyzed and discussed. These provide information to enable a better understanding of the renoprotective effects of these effective natural products from plants and microorganisms in the treatment of chronic kidney disease. Finally, we propose the steps to prove the causal role of the intestinal microflora in the treatment of chronic kidney disease by natural products from plants and microorganisms. We also assess the future perspective that natural active products from plants and microorganisms can beneficially delay the onset and progression of kidney disease by targeting the gut flora and highlight the remaining challenges in this area. With the continuous deepening of studies in recent years, it has been proved that gut microbiota is a potential target of natural active products derived from plants and microorganisms for chronic kidney disease treatment. Fully understanding the functions and mechanisms of gut microbiota in these natural active products from plants and microorganisms is conducive to their application as an alternative therapeutic in the treatment of chronic kidney disease.

The modulation of gut microbiota by herbal medicine to alleviate diabetic kidney disease - A review

The treatment of diabetic kidney disease (DKD) has been the key concern of the medical community. Herbal medicine has been reported to alleviate intestinal dysbiosis, promote the excretion of toxic metabolites, and reduce the secretion of uremic toxins. However, the current understanding of the modulation of the gut microbiota by herbal medicine to delay the progression of DKD is still insufficient. Consequently, we reviewed the knowledge based on peer-reviewed English-language journals regarding regulating gut microbiota by herbal medicines in DKD. It was found that herbal medicine or their natural extracts may have the following effects: modulating the composition of intestinal flora, particularly Akkermansia, Lactobacillus, and Bacteroidetes, as well as adjusting the F/B ratio; increasing the production of SCFAs and restoring the intestinal barrier; reducing the concentration of uremic toxins (p-cresol sulfate, indole sulfate, TMAO); inhibiting inflammation and oxidative stress.

Therapeutic mechanism and clinical application of Chinese herbal medicine against diabetic kidney disease

Diabetic kidney disease (DKD) is the major complications of type 1 and 2 diabetes, and is the predominant cause of chronic kidney disease and end-stage renal disease. The treatment of DKD normally consists of controlling blood glucose and improving kidney function. The blockade of renin-angiotensin-aldosterone system and the inhibition of sodium glucose cotransporter 2 (SGLT2) have become the first-line therapy of DKD, but such treatments have been difficult to effectively block continuous kidney function decline, eventually resulting in kidney failure and cardiovascular comorbidities. The complex mechanism of DKD highlights the importance of multiple therapeutic targets in treatment. Chinese herbal medicine (active compound, extract and formula) synergistically improves metabolism regulation, suppresses oxidative stress and inflammation, inhibits mitochondrial dysfunction, and regulates gut microbiota and related metabolism via modulating GLP-receptor, SGLT2, Sirt1/AMPK, AGE/RAGE, NF-κB, Nrf2, NLRP3, PGC-1α, and PINK1/Parkin pathways. Clinical trials prove the reliable evidences for Chinese herbal medicine against DKD, but more efforts are still needed to ensure the efficacy and safety of Chinese herbal medicine. Additionally, the ideal combined therapy of Chinese herbal medicine and conventional medicine normally yields more favorable benefits on DKD treatment, laying the foundation for novel strategies to treat DKD.

The role and mechanisms of gut microbiota in diabetic nephropathy, diabetic retinopathy and cardiovascular diseases

Type 2 diabetes mellitus (T2DM) and T2DM-related complications [such as retinopathy, nephropathy, and cardiovascular diseases (CVDs)] are the most prevalent metabolic diseases. Intriguingly, overwhelming findings have shown a strong association of the gut microbiome with the etiology of these diseases, including the role of aberrant gut bacterial metabolites, increased intestinal permeability, and pathogenic immune function affecting host metabolism. Thus, deciphering the specific microbiota, metabolites, and the related mechanisms to T2DM-related complications by combined analyses of metagenomics and metabolomics data can lead to an innovative strategy for the treatment of these diseases. Accordingly, this review highlights the advanced knowledge about the characteristics of the gut microbiota in T2DM-related complications and how it can be associated with the pathogenesis of these diseases. Also, recent studies providing a new perspective on microbiota-targeted therapies are included.

Alterations of the Gut Microbiota in Patients with Diabetic Nephropathy

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease. Accumulating studies have implied a critical role for the gut microbiota in diabetes mellitus (DM) and DN. However, the precise roles and regulatory mechanisms of the gut microbiota in the pathogenesis of DN remain largely unclear. In this study, metagenomics sequencing was performed using fecal samples from healthy controls (CON) and type 2 diabetes mellitus (T2DM) patients with or without DN. Fresh fecal samples from 15 T2DM patients without DN, 15 DN patients, and 15 age-, gender-, and body mass index (BMI)-matched healthy controls were collected. The compositions and potential functions of the gut microbiota were estimated. Although no difference of gut microbiota α and β diversity was observed between the CON, T2DM, and DN groups, the relative abundances of butyrate-producing bacteria (Clostridium, Eubacterium, and Roseburia intestinalis) and potential probiotics (Lachnospira and Intestinibacter) were significantly reduced in T2DM and DN patients. Besides, Bacteroides stercoris was significantly enriched in fecal samples from patients with DN. Moreover, Clostridium sp. 26_22 was negatively associated with serum creatinine (P < 0.05). DN patients could be accurately distinguished from CON by Clostridium sp. CAG_768 (area under the curve [AUC] = 0.941), Bacteroides propionicifaciens (AUC = 0.905), and Clostridium sp. CAG_715 (AUC = 0.908). DN patients could be accurately distinguished from T2DM patients by Pseudomonadales, Fusobacterium varium, and Prevotella sp. MSX73 (AUC = 0.889). Regarding the potential bacterial functions of the gut microbiota, the citrate cycle, base excision repair, histidine metabolism, lipoic acid metabolism, and bile acid biosynthesis were enriched in DN patients, while selenium metabolism and branched-chain amino acid biosynthesis were decreased in DN patients.

IMPORTANCE Gut microbiota imbalance is found in fecal samples from DN patients, in which Roseburia intestinalis is significantly decreased, while Bacteroides stercoris is increased. There is a significant correlation between gut microbiota imbalance and clinical indexes related to lipid metabolism, glucose metabolism, and renal function. The gut microbiota may be predictive factors for the development and progression of DN, although further studies are warranted to illustrate their regulatory mechanisms.

Regulation of the intestinal flora: A potential mechanism of natural medicines in the treatment of type 2 diabetes mellitus

Diabetes mellitus comprises a group of heterogeneous disorders, which are usually subdivided into type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Both genetic and environmental factors have been implicated in the onset of diabetes. Type 1 diabetes primarily involves autoimmune insulin deficiency. In comparison, type 2 diabetes is contributed by the pathological state of insulin deficiency and insulin resistance. In recent years, significant differences were found in the abundance of microflora, intestinal barrier, and intestinal metabolites in diabetic subjects when compared to normal subjects. To further understand the relationship between diabetes mellitus and intestinal flora, this paper summarizes the interaction mechanism between diabetes mellitus and intestinal flora. Furthermore, the natural compounds found to treat diabetes through intestinal flora were classified and summarized. This review is expected to provide a valuable resource for the development of new diabetic drugs and the applications of natural compounds.

FuZhengHuaYuJiangZhuTongLuoFang Prescription Modulates Gut Microbiota and Gut-Derived Metabolites in UUO Rats

Background

Alteration of intestinal flora and metabolites is closely related to chronic kidney disease (CKD) across early to advanced stages. FuZhengHuaYuJiangZhuTongLuoFang prescription (FZHY) is a Chinese herb that has been proven to effectively treat CKD, but the underlying mechanism is not clear.

Methods

Rats were subjected to intragastric treatment with FZHY 7, 14, and 21 days after unilateral ureteral obstruction (UUO) surgery, and kidney tissue, colon tissue, serum, and stool samples were collected.

Results

FZHY treatment effectively ameliorated UUO-induced renal function loss, renal injury and renal fibrosis, and colon tissue damage and fibrosis on day 7. The results of 16S flora analysis (day 7) showed that, compared with the UUO group, both the FZHY group and the sham group showed decreased levels of g_Monoglobus, g_Papillibacter, g_Eubacterium_nodatum, and g_Family_XIII_AD3011. Additionally, FZHY obviously induced the reduction of serum citrulline, glycoursodeoxycholic acid, 23-nordeoxycholic acid, 7-ketodeoxycholic acid, kahweol, lipoid B4, 4-(3,4-dihydro-2H-1,5-benzodioxepin-7-yl)-2-methyl-1,3-thiazole, taurolithocholic acid sodium salt, indoline-2-carboxylic acid, 5(S),15(S)-diHETE, and others and the increase of bilirubin, asparagine, and others, which were positively associated with the above four candidate bacteria. Moreover, FZHY increased the levels of ZO-1, occludin, and claudin-1 in the colonic mucosa and reduced the levels of CRP, TNF-α, IL-6, and IL-1 in the serum and LN, FN, Col-I, and Col-III in the tubulointerstitium of UUO rats on day 7.

Conclusion

Our study revealed that FZHY reduced kidney damage at the early stage of CKD by regulating the above four candidate bacteria biomarkers and gut-derived harmful metabolites, inhibiting the inflammation response and tubulointerstitial fibrosis, providing deep insight into CKD therapeutic strategy.

Lactiplantibacillus plantarum J-15 reduced calcium oxalate kidney stones by regulating intestinal microbiota, metabolism, and inflammation in rats

The prevention role of Lactiplantibacillus plantarum against the formation of kidney stones has been increasingly recognized; its mechanism, however, has mainly been focused on inhibiting the inflammation in the colon in the gastrointestinal (GI) system, and the intestinal metabolites from microflora have not been revealed fully with regarding to the stone formation. In this study, we investigated the effect of L. plantarum J-15 on kidney stone formation in renal calcium oxalate (CaOx) rats induced by ethylene glycol and monitored the changes of intestinal microflora and their metabolites detected by 16S rRNA sequencing and widely targeted analysis, followed by the evaluation of the intestinal barrier function and inflammation levels in the colon, blood and kidney. The results showed that L. plantarum J-15 effectively reduced renal crystallization and urinary oxalic acid. Ten microbial genera, including anti-inflammatory and SCFAs-related Faecalibaculum, were enriched in the J-15 treatment group. There are 136 metabolites from 11 categories significantly different in the J-15 supplementation group compared with CaOx model rats, most of which were enriched in the amino acid metabolic and secondary bile acid pathways. The expression of intestinal tight junction protein Occludin and the concentration of pro-inflammatory cytokines and prostaglandin were decreased in the intestine, which further reduced the translocated lipopolysaccharide and inflammation levels in the blood upon J-15 treatment. Thus, the inflammation and injury in the kidney might be alleviated by downregulating TLR4/NF-κB/COX-2 signaling pathway. It suggested that L. plantarum J-15 might reduce kidney stone formation by restoring intestinal microflora and metabolic disorder, protecting intestinal barrier function, and alleviating inflammation. This finding provides new insights into the therapies for renal stones.

UPLC-MS/MS method for the determination of the herb composition of Tangshen formula and the in vivo pharmacokinetics of its metabolites in rat plasma

INTRODUCTION

Tangshen formula (TSF) is a traditional Chinese medicine composed of seven medicinal herbs including Astragalus membranaceus, Rehmannia glutinosa Libosch, Citrus aurantium L., etc. which is used to treat diabetic nephropathy III, IV qi and yin deficiency and stasis syndrome. Most of the studies on TSF are pharmacological and pharmacodynamic experiments. There are few basic studies on its chemical substances, and the effective constituents are not clear.

OBJECTIVE

To analyse the main chemical components of TSF and the absorbed components in rat plasma following oral administration based on liquid chromatography tandem mass spectrometry (LC-MS/MS). Moreover, providing a rapid and valid analytical strategy for simultaneous determination of six components in rat plasma and use it in pharmacokinetic studies.

RESULTS

A total of 132 components were identified in TSF, and 44 components were identified in rat plasma after oral TSF, 35 of which were prototype components and nine were metabolic components. A sensitive and reliable LC-MS/MS method was developed for simultaneous determination of six components in rat plasma. The intra-day and inter-day precision relative standard deviation (RSD) was lower than 15%; the accuracy of low, medium and high concentrations ranged from 80% to 120%. The recovery met the requirements and the RSD of the recoveries was less than 15%.

CONCLUSION

A total of 132 components were identified in TSF. The LC-MS/MS quantitative method for the simultaneous determination of morroniside, loganin, notoginsenoside R₁ , ginsenoside Re, ginsenoside Rb₁ and astragaloside IV in rat plasma was established for the first time. The pharmacokinetic parameters are clarified, which can guide the clinical medication of TSF.

What we know about protein gut metabolites: Implications and insights for human health and diseases

Gut microbiota is a complex ecosystem of symbiotic bacteria that contribute to human metabolism and supply intestinal metabolites, whose production is mainly influenced by the diet. Dietary patterns characterized by a high intake of protein promotes the growth of proteolytic bacteria's, which produce metabolites from undigested protein fermentation. Microbioal protein metabolites can regulate immune, metabolic and neuronal responses in different target organs. Metabolic pathways of these compounds and their mechanisms of action on different pathologies can lead to the discovery of new diagnostic techniques, drugs and the potential use as functional ingredients in food. This review discusses the potential mechanisms by which amino acid catabolism is involved in microbial protein metabolites. In addition, results from several studies on the association of products from the intestinal metabolism of indigestible proteins and the state of health or disease of the host are revised.

Moutan Cortex polysaccharide ameliorates diabetic kidney disease via modulating gut microbiota dynamically in rats

Growing evidence suggests that polysaccharides from traditional Chinese medicine positively affect diabetic kidney disease (DKD) mainly through modulating gut microbiota. Previously, we demonstrated that supplementation with the polysaccharide from Moutan Cortex (MC-Pa) alleviated DKD in rats. The study intends to investigate the dynamic modulation of MC-Pa on DKD from the gut microbiota perspective. The DKD rat model was induced by a high-fat and high-sugar diet combined with streptozotocin (STZ). The rats were then supplemented with MC-Pa (80 and 160 mg/kg BW) for 12 weeks. The results showed that MC-Pa administration relieved hyperglycemia and renal injury in DKD rats. MC-Pa also reconstructed gut microbiota, improved intestinal barrier function, reduced serum proinflammatory mediators, and elevated the short-chain fatty acid (SCFAs) contents. In addition, the dynamics of Lactobacillus and Muribaculaceae_unclassified were in a dose- and time-dependent manner. Spearman correlation analysis found that a cluster of gut microbiota phyla and genera were significantly associated with DKD-related indicators. These results demonstrated that MC-Pa positively affected DKD rats by modulating gut microbiota dynamically and had potential as a prebiotic.

Punicalagin alleviates renal injury via the gut-kidney axis in high-fat diet-induced diabetic mice

Diabetic renal injury was associated with dysbiosis of the gut microbiota and intestinal barrier. Punicalagin (PU) from pomegranates potentially impacts the microbial ecosystem, intestinal barrier, and renal function. Therefore, we hypothesized that PU may improve diabetic renal injury by modulating the gut-kidney axis. The present study evaluated the effect of PU on the gut-kidney axis and kidney function in a diabetic renal injury mouse model induced by a high-fat diet (HFD). Mice were fed a HFD without PU or with at doses of 50 and 100 mg kg^-1 d^-1 for 8 weeks. Targeted metabolomics by GC-MS and 16S rRNA sequencing were implemented to determine short-chain fatty acids (SCFAs) and microbes. Further RNA sequencing analyses were performed to determine which differentially expressed genes were changed by PU. Compared with the DM model group, PU supplementation improved diabetic renal injury, ameliorated kidney architecture and function, and reshaped gut microbial ecology. Additionally, PU reversed HFD-induced gut barrier dysfunction, promoted cecal SCFA concentrations and inhibited serum lipopolysaccharide (LPS) and diamine oxidase (DAO) levels. Moreover, correlation analysis found that cecal SCFAs were significantly negatively correlated with inflammation-related genes in the kidney. The present results indicated that PU, a promising bioactive polyphenol, successfully improved diabetic renal injury, most likely through the gut-kidney axis.

Association of Lipopolysaccharide-Toll-Like Receptor 4 Signaling and Microalbuminuria in Patients with Type 2 Diabetes Mellitus

PURPOSE

Intestinal flora imbalance has been implicated in the activation of innate immunity in the kidneys. However, little is known about the potential links between lipopolysaccharide (LPS)-toll-like. receptor 4 (TLR4) signaling activated by intestinal barrier dysfunction and microalbuminuria in type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

61 patients with T2DM were stratified based on the absence (n=32) or presence (n=29) of microalbuminuria. There were also 28 control subjects. Urinary albumin excretion rate (UAER), serum levels of LPS, D-lactic acid (DLA), diamine oxidase (DAO), fasting blood glucose (FBG), interleukin-6 (IL-6), glycosylated hemoglobin A1 (HbA1c), and high-sensitivity C-reactive protein (hs-CRP), and TLR4 expression in peripheral blood mononuclear cells (PBMCs) were measured.

RESULTS

hs-CRP, IL-6, LPS, DLA, DAO, and TLR4 were markedly increased in subjects with T2DM compared to the controls (P < 0.05 for all). Moreover, LPS was positively correlated with FBG, HbA1c, hs-CRP, IL-6, UAER, DLA, DAO, and TLR4 (P < 0.05 for all). In addition, TLR4 was positively correlated with UAER, hs-CRP, FBG, DLA, HbA1c, and LPS (P < 0.05 for all). In regression analyses, TLR4, LPS, HbA1c, and hs-CRP were independently associated with UAER (P < 0.05 for all), while FBG, LPS, TLR4, and hs-CRP (P < 0.05 for all) were found to be risk factors for microalbuminuria in T2DM.

CONCLUSION

Intestinal integrity is compromised in subjects with T2DM, and the activation of LPS-TLR4 signaling might play an important role in the development of microalbuminuria in T2DM.

Protective effects of Huang-Lian-Jie-Du Decoction on diabetic nephropathy through regulating AGEs/RAGE/Akt/Nrf2 pathway and metabolic profiling in db/db mice

BACKGROUND

Diabetic nephropathy (DN) is a severe diabetic complication that is the principal cause of end-stage kidney disease worldwide. Huang-Lian-Jie-Du Decoction (HLJDD) is widely used to treat diabetes clinically. However, the nephroprotective effects and potential mechanism of action of HLJDD against DN have not yet been fully elucidated.

PURPOSE

This study aimed to investigate the potential roles of HLJDD in DN and elucidate its mechanisms in db/db mice.

METHODS

An integrated strategy of network pharmacology, pharmacodynamics, molecular biology, and metabolomics was used to reveal the mechanisms of HLJDD in the treatment of DN. First, network pharmacology was utilized to predict the possible pathways for DN using the absorbed ingredients of HLJDD in rat plasma in silico. Then, combined with histopathological examination, biochemical evaluation immunohistochemistry/immunofluorescence assay, western blot analysis, and UPLC-Q-Orbitrap HRMS/MS-based metabolomics approach were applied to evaluate the efficacy of HLJDD against DN and its underlying mechanisms in vivo.

RESULTS

In silico, network pharmacology indicated that the AGEs/RAGE pathway was the most prominent pathway for HLJDD against DN. In vivo, HLJDD exerted protective effects against DN by ameliorating glycolipid metabolic disorders and kidney injury. Furthermore, we verified that HLJDD protected against DN by regulating the AGEs/RAGE/Akt/Nrf2 pathway for the first time. In addition, 22 potential biomarkers were identified in urine, including phenylalanine metabolism, tryptophan metabolism, glucose metabolism, and sphingolipid metabolism.

CONCLUSION

These findings suggest that HLJDD ameliorates DN by regulating the AGEs/RAGE/Akt/Nrf2 pathway and metabolic profiling.

Qing-Re-Xiao-Zheng Formula Modulates Gut Microbiota and Inhibits Inflammation in Mice With Diabetic Kidney Disease

Evidence indicates that the metabolic inflammation induced by gut microbiota dysbiosis contributes to diabetic kidney disease. Prebiotic supplementations to prevent gut microbiota dysbiosis, inhibit inflammatory responses, and protect the renal function in DKD. Qing-Re-Xiao-Zheng formula (QRXZF) is a Traditional Chinese Medicine (TCM) formula that has been used for DKD treatment in China. Recently, there are growing studies show that regulation of gut microbiota is a potential therapeutic strategy for DKD as it is able to reduce metabolic inflammation associated with DKD. However, it is unknown whether QRXZF is effective for DKD by regulating of gut microbiota. In this study, we investigated the reno-protective effect of QRXZF by exploring its potential mechanism between gut microbiota and downstream inflammatory pathways mediated by gut-derived lipopolysaccharide (LPS) in the kidney. High-fat diet (HFD) and streptozotocin injection-induced DKD mice model was established to assess the QRXZF effect in vivo. Mice treated with QRXZF for 8 weeks had significantly lower levels of urinary albumin, serum cholesterol and triglycerides. The renal injuries observed through histological analysis were attenuated as well. Also, mice in the QRXZF group had higher levels of Zonula occludens protein-1 (ZO-1) expression, lower levels of serum fluorescein-isothiocyanate (FITC)-dextran and less-damaged colonic mucosa as compared to the DKD group, implying the benefit role for the gut barrier integrity. QRXZF treatment also reversed gut dysbiosis and reduced levels of gut-derived LPS. Notably, the expression of toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB), which are important inflammation pathways in DKD, were suppressed in the QRXZF groups. In conclusion, our results indicated that the reno-protective effects of QRXZF was probably associated with modulating gut microbiota and inhibiting inflammatory responses in the kidney.

Gut microbiota, key to unlocking the door of diabetic kidney disease

This review discusses the influence of gut microbiota dysbiosis on diabetic kidney disease through metabolite profile changes and immune and inflammatory mechanisms. We also elaborate on the mechanism of dysbiosis in the onset and development of other kidney diseases.

This review presents scientific evidence on the pathophysiologic links between gut microbiota and diabetic kidney disease (DKD), highlighting the influence of gut microbiota dysbiosis on DKD through metabolite profile changes and immunologic mechanisms.

Gut microbiota-derived tryptophan metabolism mediates renal fibrosis by aryl hydrocarbon receptor signaling activation

The gut microbiota has a crucial effect on regulating the intestinal mucosal immunity and maintaining intestinal homeostasis both in health and in disease state. Many effects are mediated by gut microbiota-derived metabolites and tryptophan, an essential aromatic amino acid, is considered important among many metabolites in the crosstalk between gut microbiota and the host. Kynurenine, serotonin, and indole derivatives are derived from the three major tryptophan metabolism pathways modulated by gut microbiota directly or indirectly. Aryl hydrocarbon receptor (AHR) is a cytoplasmic ligand-activated transcription factor involved in multiple cellular processes. Tryptophan metabolites as ligands can activate AHR signaling in various diseases such as inflammation, oxidative stress injury, cancer, aging-related diseases, cardiovascular diseases (CVD), and chronic kidney diseases (CKD). Accumulated uremic toxins in the body fluids of CKD patients activate AHR and affect disease progression. In this review, we will elucidate the relationship between gut microbiota-derived uremic toxins by tryptophan metabolism and AHR activation in CKD and its complications. This review will provide therapeutic avenues for targeting CKD and concurrently present challenges and opportunities for designing new therapeutic strategies against renal fibrosis.

The effects of Bushen Yiqi Huoxue prescription and its disassembled prescriptions on a diabetic retinopathy model in Sprague Dawley rats

BACKGROUND

Diabetic retinopathy (DR) is one of the most serious complications in the late stages of diabetes, with a complex mechanism. As a complication affecting local lesions, few studies have compared differences of cytokine expression in the serum and retina. Owing to the specific value of traditional Chinese medicine (TCM) to complex diseases, TCM research has recently boomed in the prevention and treatment of diabetes. Bushen Yiqi Huoxue (BYH) prescription is a Chinese herbal compound that has been independently developed by our research group and has been proved to have a positive effect on DR; however, its specific mechanism and compatibility rule remain to be further explored.

OBJECTIVE

To construct a DR model of Sprague Dawley (SD) rats, simultaneously detect multiple factor expression in the serum and retina of rats, explore the effect of BYH prescription and its disassembled prescriptions on DR, and discuss the influence of various compatibility combinations.

METHODS

BYH prescription was disassembled into two new compatibilities in the absence of Rehmanniae Radix (Yiqi Huoxue prescription, YH prescription) or Ginseng Radix et Rhizoma (Bushen Huoxue prescription, BH prescription). Male SD rats were induced using streptozotocin + high-fat and high-sugar diet to establish DR models and were divided into groups, then the intragastric administration and sampling. The body weight and fasting blood glucose of rats were continuously recorded during feeding; pathophysiological status observation of the retina by haematoxylin and eosin (HE) staining; advanced glycation end products (AGEs) and haemoglobin A1c (HbA1c) level detection in the rat serum by enzyme-linked immunosorbent assay; and the Luminex technique was used to detect the ICAM-1, IL-1β, IL-6, TNF-α and vascular endothelial growth factor (VEGF) expression concentrations in the retinal tissue and serum.

RESULTS

The results of blood glucose, body weight and HE staining proved that the model was successfully constructed, and the three combinations could reduce the retinal injury in DR rats. Serum AGEs and HbA1c levels of the model group increased compared with the control group (CG). Compared with the DR model group, only AGEs decreased in the BYH group, while the AGEs and HbA1c levels were significantly inhibited in the YH and BH groups, showing a significant correlation between the expression of AGEs and HbA1c in the serum of DR rats. In the serum of rats, IL-1β, IL-6, TNF-α and VEGF concentrations in the DR model group increased, although no statistical difference was observed in the ICAM-1 data compared with the CG. Compared with the DR model group, the IL-1β, IL-6 and TNF-α expression decreased in the BYH group. Moreover, the IL-6 and TNF-α expression decreased in the YH group and only the IL-6 expression decreased in the BH group. In the retina tissue, the model group had higher ICAM-1, IL-1β, IL-6, TNF-α and VEGF levels than the CG. Compared with the DR model group, TNF-α in the BYH group rats decreased, and the ICAM-1, IL-6 and TNF-α concentrations decreased in the YH and BH groups. Furthermore, differences in the ICAM-1 and VEGF expression in the serum and retina existed.

CONCLUSION

BYH compound and its disassembled prescriptions could improve the DR model rats induced with streptozotocin + high-fat and high-sugar diet, respectively, by inhibiting chronic blood glucose, AGEs, or inflammation response. The expression level and location of each factor are different, confirming that the effect of TCM prescriptions is not the simple addition of each single drug or its chemical components, but the rationality of its internal compatibility combination. Further, ICAM-1 and VEGF have exactly different expression levels, suggesting more attention to be paid by other researchers or doctors in future studies.

Genetic Basis of Tiller Dynamics of Rice Revealed by Genome-Wide Association Studies

A tiller number is the key determinant of rice plant architecture and panicle number and consequently controls grain yield. Thus, it is necessary to optimize the tiller number to achieve the maximum yield in rice. However, comprehensive analyses of the genetic basis of the tiller number, considering the development stage, tiller type, and related traits, are lacking. In this study, we sequence 219 Korean rice accessions and construct a high-quality single nucleotide polymorphism (SNP) dataset. We also evaluate the tiller number at different development stages and heading traits involved in phase transitions. By genome-wide association studies (GWASs), we detected 20 significant association signals for all traits. Five signals were detected in genomic regions near known candidate genes. Most of the candidate genes were involved in the phase transition from vegetative to reproductive growth. In particular, HD1 was simultaneously associated with the productive tiller ratio and heading date, indicating that the photoperiodic heading gene directly controls the productive tiller ratio. Multiple linear regression models of lead SNPs showed coefficients of determination (R²) of 0.49, 0.22, and 0.41 for the tiller number at the maximum tillering stage, productive tiller number, and productive tiller ratio, respectively. Furthermore, the model was validated using independent japonica rice collections, implying that the lead SNPs included in the linear regression model were generally applicable to the tiller number prediction. We revealed the genetic basis of the tiller number in rice plants during growth, By GWASs, and formulated a prediction model by linear regression. Our results improve our understanding of tillering in rice plants and provide a basis for breeding high-yield rice varieties with the optimum the tiller number.

QiDiTangShen granules modulated the gut microbiome composition and improved bile acid profiles in a mouse model of diabetic nephropathy

QiDiTangShen granules (QDTS), a traditional Chinese herbal medicine, have been used in clinical practice for treating diabetic kidney disease for several years. In our previous study, we have demonstrated that QDTS displayed good efficacy on reducing proteinuria in mice with diabetic nephropathy (DN). However, the exact mechanism by which QDTS exerts its reno-protection remains largely unknown. To ascertain whether QDTS could target the gut microbiota-bile acid axis, the db/db mice were adopted as a mouse model of DN. After a 12-week of treatment, we found that QDTS significantly reduced urinary albumin excretion (UAE), and attenuated the pathological injuries of kidney in the db/db mice, while the body weight and blood glucose levels of those mice were not affected. In addition, we found that QDTS significantly altered the gut microbiota composition, and decreased serum levels of total bile acid (TBA) and BA profiles such as β-muricholic acid (β-MCA), taurocholic acid (TCA), tauro β-muricholic acid (Tβ-MCA) and deoxycholic acid (DCA). These BAs are associated with the activation of farnesoid X receptor (FXR), which is highly expressed in kidney. However, there was no significant difference between QDTS-treated and -untreated db/db mice regarding the renal expression of FXR, indicating that other mechanisms may be involved. Conclusively, our study revealed that QDTS significantly alleviated renal injuries in mice with DN. The gut microbiota-bile acid axis may be an important target for the reno-protection of QDTS in DN, but the specific mechanism merits further study.

Protective Role of Tangshen Formula on the Progression of Renal Damage in db/db Mice by TRPC6/Talin1 Pathway in Podocytes

Tangshen Formula (TSF) is a Chinese Medicine formula that has been reported to alleviate proteinuria and protect renal function in humans and animals with diabetic kidney disease (DKD). However, little is known about its mechanism in improving proteinuria. The dysregulation of podocyte cell-matrix adhesion has been demonstrated to play an important role in the pathogenesis and progression of proteinuric kidney diseases including DKD. In the present study, the underlying protective mechanism of TSF on podocytes was investigated using the murine model of type 2 DKD db/db mice in vivo and advanced glycation end products (AGEs)-stimulated primary mice podocytes in vitro. Results revealed that TSF treatment could significantly mitigate reduction of podocyte numbers and foot process effacement, reduce proteinuria, and protect renal function in db/db mice. There was a significant increase in expression of transient receptor potential canonical channel 6 (TRPC6) and a decrease in expression of talin1 in podocytes of db/db mice. The results of AGEs-stimulated primary mice podocytes showed increased cell migration and actin-cytoskeleton rearrangement. Moreover, primary mice podocytes stimulated by AGEs displayed an increase in TRPC6-dependent Ca2+ influx, a loss of talin1, and translocation of nuclear factor of activated T cell (NFATC) 2. These dysregulations in mice primary podocytes stimulated by AGEs could be significantly attenuated after TSF treatment. 1-Oleoyl-2-acetyl-sn-glycerol (OAG), a TRPC6 agonist, blocked the protective role of TSF on podocyte cell-matrix adherence. In conclusion, TSF could protect podocytes from injury and reduce proteinuria in DKD, which may be mediated by the regulation of the TRPC6/Talin1 pathway in podocytes.